BC Skills Academy

LLM Inference & Large-Scale Deployment — Study Guide

An illustrated, exam-aligned study guide for serving large language models in production: how inference differs from training, the prefill/decode split and the KV-cache, batching (static/dynamic/continuous), PagedAttention and FlashAttention, quantization (int8/int4, GPTQ/AWQ/GGUF), speculative decoding, tensor parallelism, GPU-memory math, latency metrics (TTFT/TPOT), serving stacks, caching, autoscaling, cost, observability, and guardrails. Diagrams, comparison tables, and worked GPU-memory examples throughout.

Key facts

Course outline

  1. From Training to Inference — Why serving is a different problem: the forward-only decode loop, the prefill/decode split, and the KV-cache that defines LLM inference.
    • Inference Is Not Training
    • The Autoregressive Decode Loop
    • Prefill vs Decode: Two Phases, Two Bottlenecks
  2. The KV-Cache & GPU-Memory Math — Why the KV-cache exists, what it costs, and how to size weights + KV + activations for a real deployment.
    • Why the KV-Cache Exists
    • KV-Cache Memory: The Formula
    • Sizing a Deployment: Weights + KV + Activations
  3. Batching & Attention Kernels — Static, dynamic, and continuous batching; PagedAttention's paged KV; and FlashAttention's IO-aware exact attention.
    • Static, Dynamic & Continuous Batching
    • PagedAttention: Paging the KV-Cache
    • FlashAttention: Exact, IO-Aware Attention
  4. Quantization & Faster Decoding — Int8/int4 weight and activation quantization (GPTQ, AWQ, GGUF), the accuracy tradeoff, and speculative decoding.
    • Quantization: Methods & Tradeoffs
    • The Memory-Bandwidth View of Decode
    • Speculative & Assisted Decoding
  5. Serving at Scale — Latency metrics, throughput/latency tradeoffs, tensor parallelism, serving stacks, caching, autoscaling, cost, observability, and guardrails.
    • Latency Metrics & the Throughput Tradeoff
    • Scaling the Model: Tensor Parallelism & Stacks
    • Caching, Autoscaling & Cost
    • Observability & Serving-Time Guardrails